Many of us are told that, when we’re attacked, we should let it happen so that the situation doesn’t get any worse. In some cases that may be your only option. But some studies have shown that fighting back is a better option. Showing resistance and making it difficult for your attacker to do their job often helps you get to safety.
http://robertsiciliano.com/blog/2013/05/16/during-a-robbery-fight-or-comply/